In endless conveyor belt systems and the like, for example those used in mining operations, independent support stands, i.e., unconnected, except perhaps when retracted or being stored are commonly utilized to support endless conveyor belts and the like. These stands, for example, of the type referred to as pin connected trailing stands, or "pin-pull" type stands, may have diagonally disposed or "snowplow" floor engaging members so that the stands can be nested in a retracted position. The stands are slid along the surface in a group with the stands connected to each other by means of pins. When it is desired to deploy the stands, the pin or pins are pulled and the stands separated and spaced from each other into position.
Deployment of the "pin-pull" type stands is difficult and requires considerable manual effort. Sliding the stands into a nested or retracted position requires additional effort, first to ensure the proper nesting of the stands, and then to align the stands in order to reconnect the pins as each stand is moved into position. Proper spacing of these stands is difficult to maintain as such spacing requires operator judgment and attention. Occasionally during use, one or more stands may tilt and fall causing material to be spilled, occasional damage to the stands and the conveyor belt or the like, and loss of production while the conveyor belt or the like system is inoperative. Furthermore, as the number of stands in a system increase, the force required to slide the stands along the floor will increase until the strength of the brackets and pins holding the stands together may be exceeded, or the towing vehicle may lose traction attempting to overcome the tension of the conveyor belt and the like and the frictional drag of the stands. The "snowplow" configuration of the stands, desirable for nesting, further increases the frictional drag during forward movement of the system, while the difficulty of moving and aligning the stands increases to an even greater extent upon retracting or collecting the stands into the nested position.
A belt conveyor supporting system having individual stands, is illustrated in U.S. Pat. No. 4,245,738, wherein nested stands or stools are deployed spaced from each other.
The free-standing or "pin-pull" type stands are not generally satisfactory in modern mining techniques, particularly where an extensible conveyor-belt system is to be used along an angled path, or to turn a corner, frequently to turn a corner of as much as 90.degree.. The described stand units in the nested condition cannot readily be moved along an angled path or caused to turn corners.
In conveyors for other purposes, usually lightweight conveyors, for example in orchards and for handling packages, cartons, and the like, various tong or parallelogram type extendable conveyor supports have been proposed U.S. Pat. Nos. 2,590,359 and 3,294,216 are illustrative of these light-weight conveyors. In the support-system in U.S. Pat. No. 2,590,359 a rigid, collapsible frame is utilized having a collapsed and erected position, permitting operation only in the latter. The system employs connecting links having toggle action, which determines the spacing between floor supported members. The supporting frame for the conveyor is substantially rigid when erected, generally precluding bends or turns in the system when extended. An extensible boom using a scissors-type tong arrangement is utilized in U.S. Pat. No. 3,294,216 for extension of a spring conveyor and another structure, such as a cage, from a base. In such arrangement, bends and turns of the conveyor are not contemplated and floor support of intermediate elements of the system are not provided. Such intermediate support elements are required for supporting a conveyor belt handling heavy loads, such as mined material.
While specialized systems have been proposed for enabling conveyor belts and the like to assume a curved path, these systems, for example as shown in U.S. Pat. No. 4,260,053, do not lend themselves to extensible conveying of loose or broken material of considerable weight, such as mined material. Supporting the conveyor at its ends or providing occasional intermediate support, does not provide sufficient support for conveyor belts and the like for heavy loading, as encountered in mining for example.
Therefore, one object of the present invention is to provide an improved longitudinally extensible support system for endless conveyor belts and the like.
Another object of the present invention is to provide a longitudinally extensible support system for endless conveyor belts and the like in which the support members are interconnected and have improved stability as compared to conveyor belt support stands commonly utilized in the mining industry.
A further object of the invention is to provide a longitudinally extensible support system for endless conveyor belts and the like which can be automatically deployed.
Still another object of the present invention is to provide an extensible support system for supporting endless conveyor belts and the like for operation while contracted and extended.
A further object of the invention is to provide an extensible support system for endless conveyor belts and the like for supporting members of the system above the floor surface when the members are in the retracted position to facilitate movement of the system.
A still further object of the present invention is to provide an extensible support system for conveyor belts and the like which also support a cable while the system is in the retracted and extended positions.
These and other objects and advantages of the present invention will be readily apparent to those skilled in the art from the following description.